Losing Their Way: A Cohort Analysis of Retention in Care Among Adolescents on Antiretroviral Therapy in Lusaka District,Zambia

Abstract

Background

Retention in antiretroviral therapy (ART) is crucial for adherence, viral suppression, and preventing drug resistance. Adolescents (10-19 years) face retention challenges, affecting progress toward 95% viral suppression. Data on retention for this specific age bracket remains limited in Zambia.

Methods

A retrospective cohort analysis of 3978 adolescents on ART in Lusaka examined socio-demographic, clinical, treatment, and behavioral data. Kaplan–Meier estimates analyzed retention, and Cox regression identified associated factors using SPSS v29.

Results

Seventy percent remained in care, while 30% had interruptions, transfers, or death. Females (57.1%) had a higher non-retention risk (aHR: 1.21 [1.08-1.36]). Retention was lower in older adolescents (15-19 years, aHR: 0.11 [0.10-0.13]). Retention increased with early ART initiation with those starting ART at 15 to 19 years showed lowest retention (aHR: 578.50 [421.00-794.91]). Not changing ART regimens decreased retention (aHR: 0.88 [0.77-0.99]).

Conclusions

Targeted interventions should prioritize females, older adolescents, early ART initiation, and regimen changes.

Plain Language Summary

A cohort analysis of Retention in Care Among Adolescents on Antiretroviral Therapy

Background

Retention in antiretroviral therapy (ART) is crucial for adherence, viral suppression, and preventing drug resistance in people living with HIV. Adolescents (10-19 years) often struggle with ART retention, affecting treatment success toward 95% viral suppression. However, data on retention and associated factors in Zambia remain limited.

Aim

To assess retention and identify factors influencing ART retention among adolescents in Zambia to inform strategies for improving adherence and viral suppression.

Methods

A retrospective cohort analysis of 3978 adolescents registered on ART at Lusaka public health facilities from 1 January 2023 to 31 December 2023 was conducted. Socio-demographic, clinical, treatment, and behavioral data were extracted from electronic records and analyzed using SPSS version 29. Kaplan–Meier survival estimates described retention trends, while Cox proportional hazard models identified retention-associated factors.

Results

Conclusions

Targeted interventions are needed to enhance retention, particularly for females, older adolescents, and those initiated later on ART. Early ART initiation and timely regimen transitions are critical for achieving 95% retention.

Keywords

adolescents anti-retroviral therapy retention retrospective viral suppression

Introduction

HIV is a global public health threat affecting 39.9 million [36.1-44.6 million] with 1.3 million [1-1.7 million] people newly infected with HIV in 2023.¹ Africa has a disproportionately high burden, with Eastern and Southern Africa reported at 20.8 million [19.2-23.0 million] and Western and Central Africa at 5.1 million [4.5-5.9 million] people living with HIV.¹ Of the total global population living with HIV, approximately 1.55 million are adolescents.²

According to the World Health Organization (WHO), adolescence is defined as the period of life after childhood and before reaching adulthood, set at 10 to 19 years.³ Adolescents remain a particularly vulnerable population in the global fight against HIV. The developmental stage is characterized by risk-taking, sensation-seeking, and a strong orientation toward peer interactions, which can interfere with retention in care and treatment.⁴ In 2023, the WHO reported that 360,000 [240,000-480,000] young people aged 15 to 24 years were newly infected with HIV, with 140,000 [39,000-240,000] of these cases occurring among adolescents aged 15 to 19 years.² Compared to adults, adolescents and young people face additional challenges in the HIV care continuum, as they are less likely to undergo testing, access care, remain in treatment and achieve viral load suppression.^5-7 Despite advances in HIV prevention and treatment, adolescents continue to face significant challenges in accessing appropriate care and support.⁸

In a global effort to combat this HIV/AIDS epidemic, antiretroviral therapy (ART) has been a cornerstone, significantly improving the prognosis for people living with HIV/AIDS (PLHIV) while also reducing HIV-related morbidity and mortality.⁹ Since its widespread implementation, ART has curbed the transmission of the virus, leading to significant public health gains.¹⁰ The adoption of the revised Joint United Nations Program on HIV and AIDS (UNAIDS) 95-95-95 targets which aim to ensure that 95% of all PLHIV know their status, 95% of all HIV positive individuals are initiated and retained on ART, and 95% of all individuals on ART achieving viral suppression and treat all strategies (all individuals diagnosed HIV positive are immediately initiated on ART) have seen the proportion of PLHIV on ART significantly increase.^10,11 Notably, out of all PLHIV on ART by the end of 2023, 1.1 million were adolescents aged 10 to 19 years.¹² Achieving the full benefits of ART necessitates a patient journey through the HIV continuum of care, which includes HIV testing, diagnosis, linkage to ART and related health services, adherence to ART, and achieving viral suppression, all with a lifelong commitment to care.¹³ To achieve the UNAIDS targets, ART programs must ensure patients adhere to scheduled clinic visits, follow their ART regimen, and continue necessary health services,¹⁴ which are vital for optimal clinical outcomes.^15,16

Zambia has adopted the UNAIDS 95-95-95 targets alongside a test-and-treat approach, achieving significant progress in immediate ART initiations.¹⁷ However, retaining newly diagnosed individuals on ART remains a challenge, especially for ALHIV, who encounter unique barriers and are often underserved by health systems across sub-Saharan Africa.¹⁸ Regionally, public health facilities have tailored services either for pediatrics or adults creating a critical gap in care specifically tailored to adolescents.¹⁹ According to the Zambia Population-based HIV Impact Assessment (ZAMPHIA) survey, Zambia has exceeded the second and third target of the UNAIDS “95-95-95” targets.²⁰ The third 95 target refers to viral suppression, which in the Zambian context is defined as having a viral load of less than 1000 RNA copies per milliliter of blood, in line with national guidelines 17.

Despite progress toward the set targets, gaps remain in certain HIV sub-populations, particularly adolescents. The overall success in the adult population often overshadows the challenges faced by adolescents, masking their unmet targets and highlighting the need for targeted interventions to ensure equitable progress. Regional and local data on retention rates among ALHIV show considerable variation across settings. In South Africa's Ehlanzeni district, a study reported retention rates of 90.5%, 85.4%, 80.8%, and 76.2% at 6, 12, 18, and 24 months, respectively, among adolescents aged 10 to 19 years.²¹ In contrast, another study in the cape metropole observed lower retention rates of 68.6%, 50.5%, and 36.4% at 4-, 12-, and 24-month post-ART initiation.²² Conversely, a separate study reported higher retention rates of 97.7%, 94.1%, 92.4%, 90.2%, and 84.6% at 6, 12, 18, 24, and 36 months, respectively.²³ In Zambia, a study assessed the impact of evolving national HIV treatment policies on pediatric and adolescent ART outcomes. It found that retention at 6 months after ART initiation ranged from 46.7% to 63.4% among children aged 5 to 15 years and from 40.1% to 52.7% among older adolescents aged 15 to 19 years.²⁴

It is therefore critical to examine retention in HIV care among adolescents as well as the specific local factors associated with retention in HIV care to ensure equitable coverage and sustained epidemic control. The abovementioned information would assist in the design and implementation of programs and interventions to keep ALHIV in treatment and care by addressing specific risk factors and barriers. The current study specifically focused on adolescents aged 10 to 19 years to provide a more age-disaggregated understanding of retention in care, particularly considering the unique developmental, psychosocial, and structural challenges this population faces in the context of HIV treatment. Unlike some previous studies that have combined pediatric populations with adolescents, typically grouping individuals under broader age bands such as 0 to 14, 5 to 14, or 10 to 24 years, this study deliberately restricted the analysis to adolescents to avoid masking age-specific risk factors and retention patterns. This focus allowed for a more nuanced analysis of both the prevalence of retention and the associated risk factors, thereby addressing critical evidence gaps and informing the design of adolescent-responsive HIV care programs.

This article reports on the prevalence and risk factors for retention in care among ALHIV (10-19 years) on ART in Lusaka District, Zambia. To identify the factors associated with retention, we used the Behavioral Model for Vulnerable Populations (BMVP) developed by Lillian Gelberg and Ronald Andersen.²⁵ The model incorporates vulnerable domains (predisposing, enabling, and need factors) that emphasize the influence of social structures and resource availability on the health and care-seeking behaviors of vulnerable populations (see Table 1).

Table 1.

Justification of Variables Using the Behavioral Model for Vulnerable Populations.

Category	Variable	Justification
Predisposing Factors	Age, Gender, Age at ART initiation	These factors affect health-seeking behavior, developmental stage, and level of autonomy in care. While younger adolescents often depend on caregivers for engagement in treatment, older adolescents may have greater independence but are more likely to encounter stigma, which can impact retention.
Enabling Factors	Duration on ART, Current ARV Regimen, Regimen Class, Change in Regimen	Reflect treatment stability, tolerability, and provider management which may impact retention. Regimen changes can signify complications or non-adherence
Need Factors	Baseline and Latest CD4 Counts, WHO Stage, Viral Suppression, TB History, TB Prophylaxis	Indicate disease severity and clinical need, which influence motivation to remain in care. Poor health may either increase or hinder retention depending on support.
Behavioral/Health Service Factors	Optimal adherence	Strong proxy for engagement in care; poor adherence often predicts dropout
Other	Received TB prophylaxis	Indicates integration with other services and preventative care, which may improve retention

Methodology

Study Design

We conducted a retrospective cohort analysis using routinely collected data from ALHIV on ART from 1 January to 31 December 2023 in primary health care facilities and first level hospitals in Lusaka District.

Study Context

Lusaka is the capital city of Zambia, offers a multi-tiered healthcare system through various levels of service provision. In the public sector, facilities range from health posts, which are the entry-level points of care, up to specialized hospitals, classified as third-level hospitals, which provide the highest level of care. According to the master facility list, Lusaka district has thirty-six (36) health posts, thirty-one (31) health centers, five (5) first-level hospitals, and eight (8) third-level, specialized hospitals. Health posts and health centers primarily deliver primary care services, including HIV-related care. First-level hospitals serve as referral points for health posts and health centers and also offer HIV services, while third-level hospitals focus on specialized treatment for complex cases referred from the lower levels.

Study Population and Sampling

The study population consisted of all adolescents aged 10 to 19 years receiving ART and accessing ART services in Lusaka District in 2023. Records of 128,991 PLHIV attending ART services in health facilities in Lusaka District from January to December 2023 were obtained from the EHR. Figure 1 shows that of 128,991 records, 125,013 were records of people living with HIV aged less than 10 years and more than 19 years who were in care in 2023, while 3978 records were of adolescents aged 10 to 19 years during 2023.

Figure 1.

Flow Chart of Participants Selected in the Study.

Inclusion criteria:

Adolescents aged 10 to 19 years receiving ART in Lusaka District during the study period (January-December 2023).

Records available in the SmartCare electronic medical record system with valid ART status.

Exclusion criteria:

Records of individuals aged below 10 years or above 19 years.

A sample size calculation was not required for this study as all eligible records of adolescents aged 10 to 19 years on ART within the specified period were included in the analysis.

Data Collection

The primary outcome of this study was retention in HIV care. Retention in care (Yes) was defined as currently being active on ART while retention in care (No) include any interruption in treatment (IIT), transfer out (TO), or death. This definition reflects observed retention during the study period based on EMR status updates. According to the electronic medical record (EMR) system, known as SmartCare, IIT is defined as a patient missing a scheduled pharmacy refill for more than 30 days. When this occurs, the EMR automatically categorizes the patient as no longer active on treatment. Similarly, when a patient officially transfers out of a facility, especially when moving to another district, they are immediately marked as not current on ART in the EMR hence accounted for as not retained in care in this case. Routine data were collected from SmartCare, which is widely implemented in public health facilities in Zambia. The study data, gathered in August 2024, were anonymized and identified only by unique patient numbers. The predictor variables extracted include socio-demographic (gender, current age, and age at ART initiation), clinical (baseline WHO clinical stage, CD4 count (baseline and current), pregnancy, breastfeeding and history of active tuberculosis (TB)), treatment (current ARV regimen, current ARV regimen class, change in ARV regimen – defined as any modification to the patient's original ART regimen since initiation), and behavioral data (optimal adherence to ART) collected during routine clinical visits for patient management and monitoring of all patients receiving ART. Since all ART data are recorded in EHR, any missing information could not be retrieved from other sources.

Statistical Analysis

Statistical analyses were conducted using IBM SPSS Statistics, version 29.0.2.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics were applied to summarize participants’ characteristics. Continuous variables were reported as medians with interquartile ranges (IQRs), while categorical variables were presented as frequencies and percentages. Associations between retention in care and independent variables were assessed using the Chi-square test for categorical variables. Survival analysis techniques were used to evaluate time-to-event outcomes, including IIT, TO, and death. Kaplan–Meier curves were plotted to compare survival probabilities by age group and gender, and the log-rank test was applied to assess statistical differences between groups. Cox proportional hazards regression was employed to identify predictors of attrition. A backward stepwise selection method was used, retaining variables with statistical significance at p < 0.05 in the final model. Results were reported as hazard ratios (HRs) with 95% confidence intervals (CIs). All statistical tests were two-tailed.

Data Analysis

The extracted data were entered into a Microsoft Excel (Microsoft Corporation, Washington, DC, USA) spreadsheet, cleaned, and saved into a password-protected excel file to prevent any unauthorized access or alterations of the data. The excel spreadsheet was imported into the SPSS statistical software (IBM SPSS version 29.0.2.0, IBM Corp., USA) for analysis. Descriptive statistics were carried out to describe the socio-demographic, clinical, treatment and behavioral characteristics of the adolescent participants included in the study. Bivariate analysis was executed utilizing the Chi-squared test to determine the association between retention in care and the socio-demographic (age, gender, and age at ART initiation), clinical (Current WHO stage, Received TB prophylaxis, history of active TB, and viral suppression), treatment (current ART regimen, current ARV regimen class, and change in ART regimen) and behavioral (adherence) characteristics of the ALHIV.

The Cox proportional hazards model utilized a backward stepwise approach, starting with all candidate variables included in the initial model. In each step, the least significant variable was removed, continuing this process until only significant variables remained. The 95% significance level was used as the threshold for removing variables from the model. For inferential analysis, variables with missing values were treated using complete-case analysis, with cases with missing data excluded from the analysis. Survival analysis was assessed with “died”, “interruption in treatment” (IIT) and “transfer-out” as the outcomes of interest, while adolescents who remained in care throughout the period were treated as intention to treat (censored). A comparative survival analysis by age and gender was conducted using Kaplan–Meier survival curves, and HRs with p-values were reported. IIT was defined as no recorded contact with a healthcare provider following the last ART facility visit, based on the last pharmacy pick-up date in SmartCare. Observed retention in care was defined as the proportion of HIV-infected adolescents alive and on ART at 12 months. Factors influencing 12-month retention were identified through bivariate and multivariate analyses.

Reporting Standards

The reporting of this study conforms to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement: guidelines for reporting observational studies²⁶ (see Supplementary File 1 for the completed STROBE checklist).

Results

Table 2 presents the sociodemographic, clinical, treatment, and behavioral characteristics of the participants, stratified by retention status. A total of 3978 ALHIV were included in the study, with a mean age of 15.02 years (SD = 2.82) and a mean age at ART initiation of 8.27 years (SD = 5.18). Over two-thirds of participants (2783 70%) were classified as retained in care, with 30% (1195) experiencing an IIT, transferred out or died over the observation period of 12 months (Figure 2).

Figure 2.

Retention in Care Among Adolescents Living with HIV by Category.

Table 2.

Retention in Care by Socio-Demographic, Clinical, Treatment, and Behavioral Characteristics of Adolescents (10-19 Years) on ART in Lusaka District, Zambia: January 1, to December 31, 2023 (N = 3978).

			Retention in Care
Characteristics	Total (n)		Yes	%	No	%	p-Value
Total	3978	%	2783	70	1195	30
Age (in years)							0.580
10-14	1574	39.6	1109	39.8	465	38.9
15-19	2404	60.4	1674	60.2	730	61.1
Gender							0.044
Male	1801	45.3	1289	46.3	512	42.8
Female	2177	54.7	1494	53.7	683	57.2
Age at ART initiation (years)							<0.001
0-4	1099	27.6	844	30.3	255	21.3
5-9	1264	31.8	955	34.3	309	25.9
10-14	1119	28.1	712	25.6	407	34.1
15-19	496	12.5	272	9.8	224	18.7
Duration on ART (in months)							0.146
6-12	7	0.2	7	0.3	0	0
13-24	125	3.1	92	3.3	33	2.8
> 24	3846	96.7	2684	96.4	1162	97.2
Current ARV Regimen (N = 3954)							0.936
First Line	3802	96.2	2663	96.2	1139	96.1
Second Line	152	3.8	106	3.8	46	3.9
Current ARV regimen class (N = 3954)							0.302
DTG based	3916	99	2739	98.9	1177	99.3
NNRTI based	4	0.1	4	0.1	0	0
PI based	34	0.9	26	0.9	8	0.7
Change in ARV regimen							<0.001
No	2770	64.1	1783	68.8	1038	86.9
Yes	1208	35.9	1000	31.2	157	13.1
Baseline CD4 Count (in cells/mm³) (N = 1707)							0.168
< 200	155	9.1	107	8.4	48	11.2
200-349	223	13.1	165	12.9	58	13.6
≥ 350	1329	77.9	1008	78.8	321	75.2
Latest CD4 Count (in cells/mm³) (N = 2149)							0.068
< 200	74	3.4	47	2.9	27	4.9
200-349	169	7.9	121	7.6	48	8.6
≥ 350	1906	88.7	1426	89.5	480	86.5
Current WHO Stage (N = 3652)							0.614
Stage I	3581	98.1	2524	98.1	1057	98
Stage II	43	1.2	28	1.1	15	1.4
Stage III	23	0.6	17	0.7	6	0.6
Stage IV	5	0.1	4	0.2	1	0.1
Received TB Prophylaxis							0.066
No	927	23.3	671	24.1	256	21.4
Yes	3051	76.7	2112	75.9	939	78.6
History of active TB							0.437
No	3789	95.2	2646	95.1	1143	95.6
Yes	189	4.8	137	4.9	52	4.4
Viral Suppression (N = 3746)							0.573
No	301	8	208	7.8	93	8.6
Yes	3445	92	2452	92.2	993	91.4
Optimal adherence (last 2 days) (N = 3505)							0.528
No	123	3.5	83	3.4	40	3.8
Yes	3382	96.5	2372	96.6	1010	96.2

DTG, dolutegravir; NNRTI, non-nucleoside reverse transcriptase inhibitor; PI, protease inhibitor.

Note: Bold values indicate statistical significance at p < 0.05.

The majority of adolescents (n = 3155; 98.1%) were at WHO clinical stage I, and most had both baseline and recent CD4 counts ≥350 cells/mm³ (n = 1329 [78%] and n = 1906 [88.6%], respectively). Nearly all participants (n = 3802; 96.7%) were on first-line ART, with 99.1% (n = 3916) on dolutegravir (DTG)-based regimens. Optimal adherence, defined as not missing a pharmacy refill by more than 2 days, a key behavioral/health service factor in the BMVP was observed in 96.5% (n = 3382) of participants. However, this high adherence contrasts with the 70% retention in care observed during the same period, reflecting limitations in data quality within the EMR system, where incomplete or outdated visit records may inaccurately categorize some active patients as lost to follow-up.

Retention in care at 12 months was significantly higher among males compared to females (71.6% vs 68.6%, p = 0.044). Most adolescents (96.7%) had been on ART for more than 24 months. Retention was highest among those who initiated ART between 0 and 4 years of age and declined progressively among those who initiated ART at older ages (p < 0.001). Adolescents who had undergone a change in their ART regimen, a key enabling factor in the model, had significantly higher retention compared to those who had not (82.8% vs 64.4%; p < 0.001), further reflecting the influence of predisposing factors such as age at ART initiation.

Figure 3 illustrates Kaplan–Meier survival estimates for retention by age group. Older adolescents (15-19 years) were significantly less likely to be retained in care compared to younger adolescents (10-14 years) (adjusted hazard ratio [aHR] = 0.11; 95% CI: 0.10-0.13). Similarly, as shown in Figure 4, male adolescents were more likely to be retained than females (aHR = 1.21; 95% CI: 1.08-1.36).

Figure 3.

Kaplan–Meier Survival Estimates for Retention Among Younger Adolescents (10-14 Years) Compared to Older Adolescents (15-19 Years).

Figure 4.

Kaplan–Meier Survival Estimates for Retention Among Adolescent Males Compared to Females.

Table 3 presents the Cox proportional hazard analysis for retention in care. After adjusting for potential confounders using a Cox proportional hazards regression model, several factors, aligned with the BMVP domains were significantly associated with retention in care among ALHIV. Among the predisposing factors, older adolescents (15-19 years) were significantly less likely to be retained in care compared to younger adolescents (10-14 years), with an aHR of 0.11 (95% CI: 0.10-0.13). Female adolescents had a higher risk of non-retention compared to males (aHR = 1.21; 95% CI: 1.08-1.36). Age at ART initiation was also strongly associated with retention: adolescents who initiated ART at older ages had progressively lower retention compared to those who started between 0 and 4 years. Specifically, those who initiated ART at ages 5 to 9 years had an aHR of 8.57 (95% CI: 7.11-10.35), at ages 10 to 14 years had an aHR of 69.04 (95% CI: 53.91-88.42), and at ages 15 to 19 years had an aHR of 578.50 (95% CI: 421.00-794.91). Among the enabling factors, adolescents who had undergone a regimen change were more likely to remain in care compared to those who had not experienced such a change (aHR = 0.88; 95% CI: 0.77-0.99).

Table 3.

Cox Proportional Hazard Analysis of Factors Associated With Retention in Care Over 12 Months Among Adolescents (10-19 years) on ART in Lusaka District, 2023 (N = 3978).

	Total	Crude HR	95% CI	Adjusted HR	95% CI
Age (in years)
10-14	1574	Ref		Ref
15-19	2404	0.67	0.60-0.76	0.11	0.10-0.13
Gender
Male	1801	Ref		Ref
Female	2177	1.21	1.09-1.37	1.21	1.08-1.36
Age at ART initiation (years)
0-4	1099	Ref		Ref
5-9	1264	4.03	3.38-4.81	8.57	7.11-10.35
10-14	1119	13.56	11.05-16.64	69.04	53.91-88.42
15-19	496	2.04	51.43-85.99	578.50	421.00-794.91
Current ARV regimen^a
First Line	3802	Ref		Ref
Second Line	152	0.80	0.58-1.10	-	-
Current ARV regimen class^a
DTG based	3916	Ref		Ref
NNRTI based	4	0.43	0.06-3.05	-	-
PI based	34	1.02	0.55-1.90	-	-
Change in ART regimen^a
Yes	2770	Ref		Ref
No	1208	0.83	0.73-0.95	0.88	0.77-0.99
Current WHO Stage^a
Stage 1	3581	Ref
Stage 2	43	1.03	0.49-2.18	-	-
Stage 3	23	1.28	0.64-2.57	-	-
Stage 4	5	5.87	0.82-41.88	-	-
Received TB prophylaxis^a
No	927	Ref
Yes	3051	0.91	0.80-1.04	-	-
History of active TB^a
No	3789	Ref
Yes	189	0.97	0.74-1.27	-	-
Viral suppression^a
No	301	Ref
Yes	3445	1.18	0.93-1.49	-	-
Optimal adherence^a
No	123	Ref
Yes	3382	0.97	0.74-1.27	-	-

Variable left out of multivariate Cox regression.

Note: Bold values indicate statistically significant hazard ratios and adjusted hazard ratios at p < 0.05.

Discussion

The UNAIDS and WHO do not specify a single fixed percentage as the “acceptable” retention in care rate for PLHIV. However, retention in care is strongly associated with virological suppression and improved survival outcomes among individuals on ART²⁷ making it central to achieving the second and third UNAIDS 95-95-95 targets. This underscores the need for programs to attain very high retention rates, ideally approaching or exceeding 95%.

Retention in care among ALHIV (10-19 years) receiving ART in the Lusaka district of Zambia (70%) falls short of the ideal 95%. Although male adolescents constituted a smaller proportion of the study sample, on average, they had greater retention in care compared with females. This finding aligns with a retrospective cohort study conducted in the Western Cape, South Africa, which reported lower retention rates among female adolescents compared to their male counterparts.²⁸ Factors such as menstrual disorders or pregnancy tend to lead to increased health care visits by females; however, these same factors may contribute to higher dropout rates due to challenges related to healthcare access, stigma or treatment disruptions.^29,30 These observed differences by sex and age align with predisposing factors in the BMVP specifically age, gender, and age at ART initiation which shape adolescents’ developmental stage, health-seeking behaviors, and level of autonomy in managing HIV care.

We also found that older adolescents (15-19 years) were less likely to remain in care compared to younger adolescents (10-14 years). This finding is consistent with the trends reported in a study in South Africa.³¹ It is postulated that this drop in engagement in care corresponds to the post-transition period of adolescents from pediatric to adult HIV programmes.²⁸ Most adolescents included in our study were treatment experienced adolescents with a median duration on ART of 6 years with about 60% of them having initiated ART between ages 5 and 14 years. These patterns align with both predisposing and enabling factors: while age at ART initiation shapes developmental readiness for self-management, the duration on ART may reflect stability in care and familiarity with the health system.³² Early ART initiation and longer treatment experience may support better retention, particularly when caregiver support and structured transition processes are in place.²²

Comparatively, the retention rate in our study was lower than reported in similar settings at 12 months, among ALHIV enrolled in care in Mpumalanga, South Africa (85.4%),³³ and this difference may be attributed to the high-impact psychosocial interventions integrated into the Mpumalanga model, which included structured adherence support, caregiver involvement, and youth-friendly services designed to address the unique needs of adolescents. Treatment fatigue, characterized by diminished motivation to adhere to lifelong medication due to emotional, psychological, and social burdens, can lead to disengagement from care over time.³⁴ This highlights the role of behavioral/health service factors in the BMVP, specifically optimal adherence as a key determinant of retention. Adherence serves as a proxy for ongoing engagement in care, with poor adherence often preceding disengagement and treatment interruptions.³⁵

Our study found that adolescents who initiated ART between ages 0 and 4 were more likely to remain in care over 12 months. Their higher retention may be attributed to greater treatment experience, sustained caregiver support in early childhood, and a structured HIV disclosure process that facilitated a smooth transition to independent care.^31,36 Adolescents who start ART at an older age face a higher risk of non-retention, often due to initiating treatment at an advanced stage of HIV, increased autonomy leading to inconsistent health-seeking behaviors, stigma (possibly due to behaviorally acquired HIV), peer pressure, and greater psychosocial challenges, which may disrupt continuity and support.^33,37 These findings map to both predisposing and need factors. Age at ART initiation and autonomy shape long-term care trajectories, while WHO stage, CD4 count, and viral suppression status signal disease severity and clinical urgency,³⁸ both of which influence motivation to remain in care. Poor health may either increase service utilization or hinder retention, depending on the availability of psychosocial support.³⁹

In our study, adolescents on a first-line ART regimen demonstrated a marginally higher retention rate compared to those on a second-line ART regimen. This difference may be attributed to the fact that those who did not change their regimen were already on the preferred first-line, efficacious dolutegravir (DTG)-based regimen and did not require switching, whereas those who experienced a change were being transitioned to the DTG-based regimen. This switch to rescue regimens typically occurs due to poor adherence and treatment outcomes from initial first-line therapies. These poor outcomes may stem from ineffective first-line regimens, particularly in cases where resistance mutations are present.⁴⁰ Additionally, these resistance mutations can often be linked to inadequate adherence to ART, further complicating treatment efficacy.⁴¹ These findings reflect key enabling factors in the BMVP, including current regimen, regimen class, and regimen changes, which are indicators of treatment stability, tolerability, and provider management. Regimen changes often signal complications or prior treatment failure and are associated with poorer retention outcomes, particularly when not accompanied by adherence support.⁴²

Limitations

This study has several limitations. Firstly, the study analyzed secondary data from the SmartCare electronic medical record system, which may contain missing or incomplete information that could not be validated through other sources. Secondly, individuals recorded as transferred out were classified as not retained, as there was no way to determine if they continued care elsewhere. This could result in underestimation of true retention rates. Finally, no a priori sample size calculation was performed, as the analysis included all eligible adolescent records, which may limit comparability with studies using calculated sample sizes.

Conclusions

Retention in care among adolescents on ART over the 12-month observation period fell significantly short of 95%. The findings in this study underscore the importance of age-specific, gender-sensitive, and individualized ART support strategies, with particular attention to addressing the mode of HIV transmission, especially for adolescents most likely behaviorally infected, who may require targeted interventions to manage disclosure and associated psychosocial challenges, to improve retention in care. To improve retention among older adolescents transitioning from pediatric to adult HIV care, structured programs such as mentorship, peer support, and adolescent-friendly services should be strengthened to ensure continuity of care. Addressing the lower retention among female adolescents requires targeted strategies that reduce stigma, protect privacy in reproductive health services, and integrate ART care with maternal health services for pregnant adolescents. Additionally, expanding differentiated service delivery models, including multi-month ART dispensing, community-based adherence clubs, and mental health support can help mitigate treatment fatigue and promote long-term adherence. Strengthening early HIV diagnosis and initiating ART immediately can further enhance retention, while ensuring access to well-tolerated first-line regimens and providing enhanced adherence counseling for those on second-line ART will be crucial for improving overall treatment outcomes.

Supplemental Material

sj-docx-1-jia-10.1177_23259582251372443 - Supplemental material for Losing Their Way: A Cohort Analysis of Retention in Care Among Adolescents on Antiretroviral Therapy in Lusaka District, Zambia

Supplemental material, sj-docx-1-jia-10.1177_23259582251372443 for Losing Their Way: A Cohort Analysis of Retention in Care Among Adolescents on Antiretroviral Therapy in Lusaka District, Zambia by Kaala Moomba, Emeka F Okonji, Talitha Crowley and Brian Van Wyk in Journal of the International Association of Providers of AIDS Care (JIAPAC)

Footnotes

ORCID iDs

Kaala Moomba

Emeka F Okonji

Talitha Crowley

Brian Van Wyk

Ethical Approval and Informed Consent Statements

Ethics approval was obtained from the University of the Western Cape Biomedical Research Ethics Committee (reference number: BM24/3/4), the Mulungushi University School of Medicine Ethics Committee (reference number: SMHS-MU2-2024-04), and the Zambia National Health Research Authority (reference number: NHRA1186/15/05/2024). Approval for the study and access to the data were obtained from the Zambia Ministry of Health (reference number: MH/101/22/3). During data extraction, no personal identifying information such as patient names, surnames or identity numbers, were extracted from the electronic database to ensure complete anonymity and protection of personal information. Informed consent was waivered by both ethics committees for this phase of the study; therefore, no informed consent process was required since data was extracted from a routine database.

Author Contributions

BvW and KM conceptualized the study. KM conducted the literature review. KM did the analysis with the support of EO. KM wrote the first and final draft of the article. BvW and TC supervised and assisted at all stages in the write up. All authors have read and approved the final article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data Availability Statement

The data set used is available from the corresponding author upon request.

Supplemental Material

Supplemental material for this article is available online.

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Supplementary Material

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